Method of producing chemically self-copying or self-containing paper

Abstract

A chemically self-copying paper intended for use in the combinations of a top sheet (CB), bottom sheet (CF) and one or more interleaving sheets (CFB) or a chemically copying, self-containing paper. The paper is formed of two fiber layers manufactured in separate wire sections and couched together while wet. The wire side of the upper fiber layer and the top surface of the lower fiber layer are couched together. The components inducing the color reaction are contained in the upper fiber layer which has been in contact with a smooth-surfaced press roll during the production of the paper.

We claim: 
     
       1. A method of producing a chemically self-copying paper intended for use in the combinations of a top sheet (CB), bottom sheet (CF) and one or more interleaving sheets (CFB) or a chemically copying, self-containing paper, said method comprising the steps of: couching together, while wet, two fiber layers manufactured in separate wire sections, the wire side of the upper fiber layer and the top surface of the lower fiber layer being couched together to form a couched web in which the upper fiber layer contains components inducing a color reaction; and   conveying said couched web through a single-felted press nip formed by a felt surface a smooth surface, so that said upper fiber layer containing the components inducing the color reaction contacts said smooth surface and said lower fiber layer contacts said felt surface.   
     
     
       2. A method as claimed in claim 1, wherein said bottom layer is made of paper stock and said top layer is made of paper stock mixed with active clay. 
     
     
       3. A method as claimed in claim 2, wherein the bottom surface of said bottom layer is coated with microcapsules. 
     
     
       4. A method as claimed in claim 1, wherein said bottom layer is made of paper stock and said top layer is made of paper stock mixed with microcapsules. 
     
     
       5. A method as claimed in claim 1, wherein said bottom layer is made of paper stock and said top layer is made of paper stock mixed with active clay and microcapsules. 
     
     
       6. A method as claimed in claim 5, wherein the bottom surface of said bottom layer is coated with microcapsules.